Input into the equilibrium program consists of five parts: thermodynamic data, reactant data, omitted species (optional), inserted species (optional), and namelist data (Table 3). Namelist was originally input as a $NAMELIST option available on the IBM 7090 computer but was removed to make the program adaptable to most machines.

The first card is a code card with the word THER (Table 4) indicating coefficient cards follow. The coefficient cards consist of five cards per specie followed by a code card with the word ENDD, indicating all the coefficient cards have been read. The coefficient card format has been altered to allow for both a larger name of a species and molar volume for the condensed species.

The first card is a code word with the word REAC (Table 5) which indicates one to fifteen reactant cards follow. Control is returned to MAIN when a blank card has been encountered. The program will consider from one to fifteen different elements. If there is a value other then zero for the entire BASE and TOP values (Appendix C), the program is considering an ALTER problem where only the mole fraction of one or more reactants are to be decreased or increased. In the first set of sample reactant cards in Table 6, three composition points will be considered where the MgO-CaO ratio varies from 1:3 to 3:1 while H2O remains constant.

The program is considering a SYSTM problem if the BASH and TOP values on the third reactant card are equal to zero and there is a value for TRI (Appendix C). A SYSTM problem is one where the program will consider a complete ternary system by considering only two reactants at a time and then all three reactants. The second set of sample reactant cards in Table 6 will create 63 composition points. The first set of 9 points considers varying ratios of MgO-CO2 the second set of 9 points considers varying ratios of MgO-H2O and the last set of 9 points considers varying ratios of CO2-H2O. At this point, H2O is set to O.1 moles and the MgO-CO2 ratio varies from 1:8 to 8:1. This procedure is repeated as H2O is incremented by O.1 and held constant while the MgO-CO2 ratio upper limit is decreased by O.1 until the final composition is 0.8 moles H2O, and O.1 moles MgO and CO2. When the BASE value is equal to zero and the TRI value is not equal to zero, then the program considers one type of a PLUS problem, adding

one reactant to the system at a time in the order they appear on the reactant cards. The first composition point created by the third set of reactant cards in Table 6 will consider the mixture MgO-Al2O3. SiO2 is added to the system for the next composition point, and CaO is added to the system for the final composition point.

If the BASE value is equal to zero and TRI not equal to zero, the program considers another type of a PLUS problem where the program considers a ternary system with all the reactants present. The first composition point in the last set of reactant cards in Table 6 considers the mixture of O.1 moles MgO, 0.4 moles CO2 and 0.2 moles H2O. H2O is held constant while the ratio of MgO-CO2 varies from 4:1 to 1:7. H2O is then incremented by O.1 while the upper limits of MgO and CO2 are decreased 0.1 moles until the final mixture of 0.1 moles MgO, O.1 moles CO2 and 0.5 moles H2O is obtained.

There should be a slight excess of oxygen included in the system (for problems involving condensed species) in order for the program to reach convergence.

These cards have the code word OMIT or INSE in the first four columns, and contain one or two species which are to be omitted or considered. The first species is left justified in columns 9-32, and the second species is left justified in columns 47-78. Additional cards may be used for up to 100 species and these cards are optional.

The first card contains the code word NAME indicating that namelist data follows (Table 7). Included are the case number, RSIZE value, TRI value, TEM option, T values, and P values. The RSIZE value controls the size of the mole fraction values less then 5 x 10^-7 to be printed. The present size control factor in EQLBRM is equal to 18.420681 which allows values with a mantissa of -11 to be printed out. Increasing the RSIZE value by a factor of ten will result in increasing the absolute value of the mantissa by a factor of four. If RSIZE is not equal to zero the present SIZE value is replaced by the value given in RSIZE. The program terminates when a card containing the word STOP is read.

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